How can Harry Potter just wave his wand and make things happen?
–
coleopteristAug 31 '13 at 5:47

Behind an event there must be a reason. Even a magic story.
–
bayuahAug 31 '13 at 11:51

2

There doesn't have to be a logical or reasonable explanation. How can Neverland exist? Who says pixies have pixie dust that can make someone fly under the right mental conditions? In what universe (other than Neverland) does a wooden sword stand a chance against a metal one? Why does it stand a chance within Neverland? Magic is the explanation as to why his shadow can be a separate entity from himself.
–
Bon GartAug 31 '13 at 21:24

What do I mean by the reason is, there is definitely an underlying story that statement. Such as dialogue and/or action in the story.
–
bayuahSep 1 '13 at 2:44

2 Answers
2

In these films, it is depicted that Peter and his shadow can be separated. Although the same person, Peter and his shadow can be considered as separate bodies. Like how in some films, when a hand gets separated from the body, it continues to act independently. Or when someone is beheaded, their body tries to find the head back.

Peter Pan got separated from his shadow as depicted in the two films -

In the film, while Peter was visiting the Darling household to listen to stories, the Darling's dog Nana barked at the intruders and while Peter escaped, his shadow was captured. That night, Wendy Darling discovered the shadow and stored it in her draw to prevent it from getting into trouble. The next night, Peter and Tinker Bell returned to retrieve it. When they found it, they accidentally woke Wendy. As Peter attempted to restore it with soap, Wendy preferred the proper way and sewed it back. - Peter Pan (1953)

...that night, Wendy catches a glimpse of Peter hovering over her bed that night and her nursemaid and dog Nana steals his shadow just as he escapes. Wendy is caught drawing Peter in her book in school the next morning. While chasing the delivery boy carrying a letter from Wendy's teacher to Mr. Darling at the bank, Wendy and Nana literally crash into him and spoil his chances of impressing his superiors. Mr. Darling chains Nana outside and reprimands Wendy before he, Mrs. Darling leave for a party, leaving the children with Aunt Millicent. Peter visits Wendy again, who sews his shadow back on. - Peter Pan (2003)

Hence it seems that his shadow and him both have a playful personality. While it was sewed back up again, the shadow may continue to play with Peter Pan by being separated and teasing him. Though after being sewed back up, the shadow is now a part of Peter.

could probably have done a better job phrasing it.. but, my point was that you can always prove that you're right, if you are in fact right. Simplest way is to provide an excerpt from a book, dialogue (or action) from a movie or quote an article/interview etc, just like kicker did in his answer.
–
TomAug 31 '13 at 13:03